Although Hagel has not yet been officially nominated to succeed Leon Panetta, opposition to him has already surfaced from members of both parties, the Los Angeles Times reported Friday.

Obama’s selection of Hagel — a Vietnam War veteran who served two terms in the Senate before retiring in 2008 — would reinforce an image of bipartisanship for his administration, the newspaper said. Robert Gates, a Republican who headed the Pentagon under the George W. Bush administration, was retained by Obama when he took office in 2008.